SEOUL, Sept 6 (Reuters) - Japanese Prime Minister Fumio Kishida makes a whirlwind visit to South Korea on Friday, seeking to seal a newfound partnership between the neighbours which will be tested by imminent changes of leaders in Tokyo and Washington.

Prodded by U.S. President Joe Biden, Kishida and South Korean President Yoon Suk Yeol orchestrated an about-face in ties that had sunk to their lowest level in decades amid acrimonious diplomatic and trade disputes over Japan's occupation of Korea from 1910 to 1945.

The leaders will review progress on their efforts to step up cooperation between the countries and discuss ways to deepen their partnership, according to Yoon's office.
Kishida has announced he would step down in September and Japan's ruling Liberal Democratic Party will hold elections on Sept. 27 to choose his successor.

Yoon and Kishida will hold a summit meeting Friday afternoon. Kishida is expected to return to Tokyo on Saturday.

On his farewell visit, Kishida will seek to push the ties forward, broadening the relationship to partners working closely together on the international stage, a Japanese foreign ministry official told a briefing.

Their meeting will also be watched for any outcome of ongoing discussions between the two countries on evacuating each others' citizens from an emergency in a third country and expediting border checks for travellers.

Yoon has made it a diplomatic priority to mend ties with Japan and improve security cooperation to tackle North Korea's military threats.

At a summit with Biden at Camp David last year, the three leaders committed to deepen military and economic co-operation, agreeing to initiatives explicitly designed to prompt long-term partnership, a senior U.S. official said.

The United States is confident Kishida's successor will be as committed to continuing the renewed alliance and that "all of these projects we've been working on together are going to continue at pace under new leadership," Mira Rapp-Hooper, senior official at the White House National Security Council, said.

"Both Prime Minister Kishida and President Yoon took on a great deal of personal risk and political risk to move forward the warming of their bilateral ties in ways that prior governments just hadn't been able to accomplish," she said.

Despite the public expression of lasting partnership from the three capitals, there is lingering question whether the Asian neighbours can maintain the kind of genuine rapprochement that will put their historic woes behind with new leaders in place.

"Even if a country's foreign policy is dictated by its national interests and its values, the changes of government bring changes at least in the tones and approaches of foreign policy," said Kim Hyoung-zhin, former South Korean deputy foreign minister recently studying in Japan.

Kishida is likely to be met by protesters in Seoul who say Tokyo has not done enough to atone for its wartime past.